The invention relates to a movable crane arrangement that comprises a main girder for a trolley; end girders with running wheels to be supported on both ends of the main girder; and running platforms for the running wheels of the end girders. The invention also relates to a method for erecting such a crane arrangement.
Publication FI 124609 B discloses a movable bridge crane arrangement that is suitable for use in field conditions, such as areas of crisis. A crane bridge with its winch is arranged on top of two containers positioned at a distance from each other to be movable on a support structure arranged at each time. Each support structure comprises a trussed structure built on top of the containers at a specific height above them to obtain the required lifting height. The space between the containers and trussed structure defines the working area of the bridge crane.
This crane arrangement that seems simple as such has some drawbacks, however. Firstly, this solution requires a separate auxiliary crane for erecting the actual crane arrangement. Transporting this type of auxiliary crane cross-country also requires additional arrangements. At the same time, erecting the crane arrangement takes too much time, which increases costs. To align two containers and to place them at the same height for a correct movement of a crane bridge may also be arduous, especially with a very uneven terrain. The strictly limited area between the two containers also restricts operations and logistics below the crane, when it is only possible to go under the crane from the open ends.